This isn't really a direct "money/cash discount" but for those on the old TPG ADSL2+ 30GB or 50GB plans at $49.99 and $59.99 respectively, you can now have your plan upgraded and 20GB increased on your quota for free as thats the new plan deals with TPG. however they are not autmocatically upgrading anyone unless you personally log into:
-> Account Management
-> Change your plan (under account management)
-> Start change of plan
-> Tick the relevant box. i.e the 50GB for the original 30GB quota, or 70GB for the original 50GB quota free.
There is no extra charge, or change to your plan/contract - (only your billing cycle will reset)
Thats an extra 20GB free.
Its usually an extra $30-$40 for 20GB with other providers
Good deal. Has been available for months though. But good if you didnt know :)